Lofrans' Anchor Windlass Technical Information
Building a windlass, it is extremely important to select light weight, high mechanical strength and corrosion proof materials to increase durability by chemical or galvanic treatments thus improving their anti-corrosion properties. It is essential to manufacture and design all the windlasses' components, avoiding the use of motors, gearbox or other components not coming from marine fields, certainly more economic, but far less appropriate in the harsh environment that yachts and boat find themselves sailing in. For this reason, all the Lofrans’ windlass components are designed and manufactured for a marine environment, despite the increase on our costs in comparisons with industrial components available on the market.
Hot forged components, e.g. wingnut, gypsy, gear wheel, clutches are supplied on the most of our windlasses. The hot forging process is more expensive than the traditional casting process, but provides high mechanical strength components, a more compact molecular structure and a better surface condition.
List of materials on some relevant anchor windlass components
- The main shaft is in stainless AISI 431 with a high mechanical strength.
- The body of the windlass, the drum and various components are made in a special alluminium alloy, polished and anodised or powered by a white polyester paint.
- The wormwheel is in alloy bronze - worm is in 38NCD4 steel.
- Screws and outer components are in stainless AISI 304 or AISI 316.
Gearbox For Vertical Models
Our gearbox at high mechanical efficiency are designed and made for marine use. The ratio from 1/50 up to 1/75 is the right compromise between performance and speed. The long life oil bath lubrification protects the internal components of the gearbox from wear and tear and reduces the noise. The gear case is black anodised for a long-life protection.
Our electric motors are designed and made for marine use.
They have particular features:
- Manufactured IP 56 degree of protection (DIN 40 050) - protection against deckwater
- Shaft, screws, nuts and cover made in stainless steel
- Electric motor case protected by a black paint
Most of Lofrans' electric motors are series-wound. They have the advantage in comparison with the less expensive permanent magnet motors to produce an initial starting torque which can be useful in critical situations.
How To Read The Technical Data
For each model it is indicated the haulage speed at a specific load, in kilogrammes. This specific load was chosen according to the features of the windlass and their average uses.For instance a 400 Watt model we considered a specific load of 25 Kgs, for a 1000 Watt model the specific load is 50 Kgs.Naturally powerful models ask for greater specific load. It is important to consider the haulage speed of the windlass depending on the lifting load, increasing when the load is lower, so the electric motor of the windlass change speed in order to the request torque to lift chain and anchor.
It is the maximum pull that a windlass can provide for a few seconds. This is measured by a dynamometer put between the gipsy and the bow roller. The greater this value the more the windlass is able to get the anchor afloat.
This value does not coincide with the maximum lifting ability of the windlass, which is influenced by some factors, e.g. using a medium quality bow roller and with a working angle of 90 degrees, the real maximum lifting ability is approximately half of the maximum pull.
The values are reliable during the recovery of the chain under normal conditions. Even the current draw changes according to the load being lifted. A brief peak of current, superior of what indicated, it is possible when you get the anchor afloat.
This catalogue states many technical facts about the performance of our windlasses. It is important to know these specifications have been extracted from real tests, made in our factory, under fixed and repeatable conditions.
The data we provide can not always be compared to what declared from other windlass manufacturers, because test criteria and tools may differ.
The type of bow roller, the type and capacity of batteries, the allowance in efficiency between electric motors and other factors, could lead to different values from what we pubblish in this catalogue.
Lofrans’ is committed to the improvement constantly of its products. For this reason Lofrans’ reserves the right to alter and modify its products without prior notice.
All the informations given here is intended to be a guide only.